If we use a dash line type and set the overall linetype factor to 100 on a drawing (plan of 20metres x 20 metres approx) and then come to print it on A3, the linetype is not being scalled back from 20metres to suit the page extents.

So instead of lots of dashes we see just 2 strikes across the page. For now we set the linefactor low, which is good for printing, but now appears a solid line in the display unless we really zoom in.